Impact antispark alloy for machine parts

ABSTRACT

A copper-based alloy also including aluminum and nickel and, additionally, chromium and zirconium, with all of the above components are taken in the following weight percent: ALUMINUM - 11.7-12.1 NICKEL - 7.5-8.2 CHROMIUM - 0.55-0.65 ZIRCONIUM - 0.25-0.37 COPPER - THE REMAINDER An advantage offered by the proposed alloy is that owing to the optimum composition of the alloy, said alloy possesses high physical and mechanical properties and is useful for manufacturing machine parts and tools noted for their strength, hardness and the absence of sparking.

United States Patent [191 Katsitadze et al.

[ IMPACT ANTISPARK ALLOY FOR MACHINE PARTS [76] Inventors: Shota Semenovich Katsitadze, ulitsa Paliashvili, 102, kv. 4; Dzhansug llich'Chkonia, ulitsa Kipshidze, 5, kv. 24; Alexandr Petrovich Martiashvili, ulitsa Paliashvili, 82, kv. 6, all of'Tbilisi, USSR.

22 Filed: 061.24, 1972 21 Appl.No.:300,305

' 52 us. (:1 .;..'7s/159,75/153,75/162 51 rm. c1. ..C22c 9/06 [58] Field ofSearch ..75/153,159, 162

[56] References Cited UNITED STATES PATENTS 1,667,966 5/1928 Corson.... 2,810,641 10/1957 Roberts... 3,253,911 5 1966 Cairns 3,297,497 1/1967 Eichelman et al. 75/162 X Feb. 19, 1974 3,366,477 H1968 Eichelman 6161. 75/162X Primary Examiner-Charles N. Lovell Attorney, Agent, or Firm-John C. Holman ABSTRACT A copper-based alloy also including aluminum and nickel and, additionally, chromium and zirconium,- 0 with all of the above components are taken in the following weight percent:

aluminum l l.7-l2.l

nickel 7.5-8.2 chromium 0.55-0.65

zirconium 0.25-0.37 copper the remainder 1 Claim, N0 DrawingsI IMPACT ANTISPARK ALLOY FOR MACHINE I PARTS The invention relates to non-ferrous metallurgy and more particularly to alloys of precipitation hardening, which are used for manufacturing machine parts that do not cause sparking in mutual striking or upon striking other machine parts.

Copper-based alloys including aluminum amounting up to weight percent and, up to 10 weightpercentof various additives of which nickel may make up to 2 weight percent, iron 4.5 weight percent, and manganese 1.7 weight percent are known in the art (cf. French Pat. No. 1.176.757, cl. C22c, 1959).

As is known, the heat treatment of such alloys'results in the separation of the dispersion particles of the intermetallides (Al Ni Fe), thus making said alloys stronger and harder.

A serious disadvantage of the known alloys is that they contain an explosion and risky element iron, which markedly reduces the sphere of application of said alloys in the manufacturing of antisparking tools.

It is an object of the present invention to eliminate the abovementioned disadvantage.

Another object of the invention is to increase the strength and hardness of an alloy.

Another object of'the invention is to obtain an optimum composition of the components providing high physical and mechanical properties for alloys and precluding sparking upon impact.

The element Zr also causes a reduction of the grainsize, which positively affects the strength of the alloy and reduces tendency to overheat at hardening temperatures.

' The following is a detailed description and an exemplarly embodiment of the proposed invention.

The proposed alloy contains in weight percent aluminum- 1l.7-12.1; nickel 7.5-8.2; chromium 0.55-0.65; zirconium 0.25-0.35, with copper constituting the rest of the alloy composition.

With the aluminum amounting to 12 weight percent, the alloy tends to become more brittle, and in order to increase the viscosity of said alloy, it is necessary to raise the nickel content to 8 percent.

' The increase in the nickel content makes the sphere of the brittle Y2 phase dependent upon a higher content 0f aluminum. That means that, with such percentage of aluminum, the separation of the 7 phase occurs at a lower rate than is the case with a lower nickel content.

In nickel casting, the alloy offers the following indices for its physical andrnechanical properties:

fg? 80-85 kglmm 0 =65-68 kglmm a 2.5-3 kg/cm 8.= 3-4 percent; and H 290-310.

The alloy thus produced was subjected t0.thermal treatment to secure higher strength.

The following is a table characterizing the mechanical indices of the proposed alloy:

Mechanical indices Variations of thermal treatment kg/mm kg/mm kgm/cm for -40 min.

These and other objects of the present invention have been achieved by providing an alloy for manufacturing machine parts that does not cause sparking upon impact, and which is based on copper but also includes aluminumand nickel, with said alloy additionally containing, according to the invention, chromium and zirconium, with all of the abovementioned components taken in the following weight percentage:

aluminum 11.7-12.1 nickel 7.5-8.2 chromium 0.55-0.65 zirconium 0.25-0.35 copper the remainder In thermal treatment according to the first variation,

a-separation of the NiAl and NiAl phases are observed, as well as the Cr- Zr .In thermal treatment according to the second variation, in addition to the above phases, a partial disintegration of phase ,8 into a 'y is observed. As phase 7 is superhard, the effect of the alloy hardness increase was obvious.

Thermal treatment according to the third variation ensures a complete disintegration of phase 018 into a 1- The proposed alloy is characterized by a high ratio lq/L ratio both in the as-cast and, particularly, the thermally treated state.

Both the as-cast alloy and the thermally treated alloy do not cause sparking even in the case of an impact against a steel plate with a force of kGrn.

Adequately high mechanical properties (0' B 0' and i 1 ofthg proposed alloy make it quite useful in ma- I nickel 7.5-8.2 chromium 0.55-0.65 zirconium 0.25-0.35

copper the remainder to percent.

l IR I. III F 

